[Crash-utility] [crash patch] Compute init_thread_union size

[Mike Galbraith]

On Thu, 2018-04-05 at 09:27 -0400, Dave Anderson wrote:
> 
> ----- Original Message -----
> > Greetings,
> > 
> > I know absolutely nothing about how crash maintenance is done, and very
> > damn little about crash's gizzard, so please consider the below a bug
> > report, a patch.. or bloody annoying spam, as you see fit.
> 
> Hi Mike,
> 
> No, it's most definitely appreciated.  Normally patches are posted on the
> crash utility mailing list (crash-utility at redhat.com), but this is fine.
> 
> And speaking of the mailing list, there was a bug report and subsequent 
> thread yesterday concerning this issue:
> 
>   https://www.redhat.com/archives/crash-utility/2018-April/msg00000.html
> 
> It was unresolved because the thread_union still exists in the most
> recent upstream sources, and I can still see the union declaration
> in the most recent Fedora kernel.

It still exists, but...

homer:..kernel/linux-4.15 # objdump -t vmlinux|grep thread_union                               
ffffffff81e00000 g     O .data  0000000000004000 init_thread_union
                                            ^^^^
homer:..kernel/linux-master # objdump -t vmlinux|grep thread_union
ffffffff81e00000 g       .data  0000000000000000 init_thread_union
                                            ^^^^

...it's size went missing at the referenced commit.

	-Mike